Twinkle's UI isn't quite as info rich (like when you click on someone's tweet) as Twitterific's, and you can't check out a tweet someone is replying to like you can in Twitterific. But, it doesn't seem as prone to slowdown (Twitterific can absolutely drag if you're scrolling through a lot of tweets), and I dig the easy-to-digest convo bubble layout. Also, there's no ads for the free (and only) version of Twinkle. But it's the location stuff that really put it over the top. [iTunes, Tapulous]

Note: It looks like Twinkle automatically adds "Twinkleking" (their official user) to your followed list, which isn't cool. Remember to remove this if you don't want to follow them.